The Boston Celtics' most encouraging player for the month of March? You could make a case that, in limited floor time, it was rookie point guard Phil Pressey, given the way he often spearheaded a second unit that played some of Boston's most inspired basketball.

Small sample size aside, what both the stats and eye test tell you as the calendar shifts to the final month of Boston's basketball season is that Pressey is making obvious progress in an often frustrating season for the Celtics.

Even Rajon Rondo is a fan of young Pressey (left). During Monday's game, color commentator Rondo said: "For being in this situation, he's a rookie, not knowing when he's going to play ... he's been terrific." Jared Wickerham/Getty Images

Consider this:

• Over 177 minutes of floor time in 13 appearance in March, Pressey was a team-best plus-35 in plus/minus, one of only five players -- all limited-minute reserves -- to finish in the positive. Starting point guard Rajon Rondo was minus-113 over 442 minutes in 12 appearances (while Jeff Green was a team-worst minus-120). Given Boston's lack of success -- the team finished 3-12 for the month -- it's no surprise that the starters were in the negative, but Pressey's number simply reflects positively on the team's performance during his court time.

• Maybe the more encouraging numbers come in Boston's ratings (points scored/allowed per 100 possessions) with Pressey on the court in March. Pressey owned a team-best offensive rating of 109.7, which was nearly nine points higher than the team's average (100.8) for the month. What's more, his defensive rating was 98.7, or 9½ points less than the team's cringe-worthy average (108.2).

Again, we'll stress that these are very small samples and that increased floor time against opposing teams' top units would almost certainly cause a downturn. But Pressey is thriving in his limited role and showing the sort of progress that must help coach Brad Stevens sleep at night, given the team's record.

One night after D.J. Augustin went off for a career-high 33 points during Chicago's win in Boston on Sunday, it was Pressey whom the Celtics tasked with slowing him when the second units were on the floor. Pressey struggled at times to stay in front of the speedy Augustin, particularly in the pick-and-roll, but more than held his own.

According to defensive data logged by Synergy Sports, Pressey is credited with defending five possessions finished by Augustin. Those plays accounted for three missed shots, a turnover and a foul, when Kelly Olynyk was whistled for bumping Augustin while shuffling over with help defense.

For the month of March, Synergy data reveals that Pressey allowed a mere 0.717 points per possession, with opposing players shooting just 32.7 percent against him. For the season, among players with a minimum of 350 possessions defended (Pressey's total through 62 appearances), Indiana's David West tops the league at 0.745 points allowed per play.

Pressey is allowing 0.846 points per play overall this year, but that number has steadily improved, and maybe the most encouraging part is that opposing players turn the ball over on 14.9 percent of his defended possessions. Going back to that 350-play minimum, that ranks Pressey 12th in the league in Synergy's turnover percentage.

There is no masking Pressey's weakness. He remains one of the league's most inefficient offensive players when it comes to shooting. Synergy data shows him averaging a mere 0.572 points per possession, which ranks dead last among the 148 total players with at least 250 possessions finished this season.

To be fair, Pressey has made progress. He had his best month of the season, shooting 35 percent overall from the floor in March, including 35.3 percent beyond the 3-point arc. But let's remember he's a pass-first guard, and the more encouraging number is that he averaged a season-best 3.8 assists in March.

During Monday's game, Rondo, serving as color commentator during the broadcast, was asked about Pressey's development.

"For being in this situation, he's a rookie, not knowing when he's going to play, when he's going to start, when he's going to get minutes, he's been terrific," said Rondo. "He's very professional. He's been in the gym working extremely hard."

As Rondo was talking, Pressey blew past Augustin on a drive and delivered a layup.

"Great drive by Phil," offered Rondo, laughing as play-by-play man Mike Gorman noted it was right on cue. "I'd like to see him do that more. He's a pass-first point guard like myself, but he's so quick, he can get in there, throw up floaters, a couple layups, and create shots for himself as well."

The Celtics signed Pressey, an undrafted free agent, to a three-year contract last summer after he played his way onto the team at summer league. The final two seasons are nonguaranteed, adding some uncertainty to his future, but considering he'll make just $816,482 next season, there's good reason to believe he'll be back on the bench.

If Pressey can develop his jumper, and he works relentlessly at it before and after practices, he's got the passing and defensive skills to carve out a reserve role on any team. Ironically, he's the sort of steady ball handler the Celtics so desperately needed behind Rondo in recent seasons.

For now, the encouraging sign for Pressey is his progress. Even as the Celtics have gotten healthier, with Avery Bradley and Rondo finally getting more minutes together in the starting backcourt, and even with Jerryd Bayless' minutes rising in a reserve role, Pressey has still found a way to impact the game when he's called upon.